Geothermal Home Heating and Cooling
Green Building and Saving on Utility Bills with a Heat Pump
Oct 26, 2008
What exactly is this thermal energy? Although the seasons cycle and we constantly seem to be rotating through our summer and winter wardrobes, the temperature in the upper ten feet of the earth's surface, in applicable areas, remains surprisingly constant at 50 to 60 degrees Fahrenheit (or 10 to 15.5 in Celsius).
How Environmentally-Friendly are Geothermal Heat Pumps?
In a nutshell, very. In fact the Environmental Protection Agency (EPA) reports that they are the most cost-effective, energy-efficient, and environmentally clean units available in the residential cooling and heating market today.
Further, the EPA reports on the green facts in commercial plants for comparison:
- Geothermal uses no fossil fuel.
- A commercial plant releases less than 1% of the carbon dioxide emissions than a fossil fuel plant does.
- A commercial plant releases 97% less of the acid rain that a fossil fuel plant does.
This is Not a Recently Developed Home Temperature Technology
In fact, Geothermal Heat Pumps have been in use since the 1940s. Their popularity has gone up along with upwardly spiraling utility prices, including electricity, heating oil, and natural gas.
Researching the market can be confusing; they're also called water-source heat pumps, geo-exchange, ground-source, and earth-coupled. Regardless of what the salesman calls it, the units offer triple duty – heating, cooling, and helping to heat water! Just the thing to combine with a tankless water heater.
What to Look for When Going Thermal and Green
For the ultimate in green appliances, look for the Energy Star label. Anther thing to look for is the COP (Coefficient Of Performance). This is expressed as a BTU unit (British Thermal Unit) and ideally should be 2.8 or above.
The EER (Energy Efficiency Ratio) should be 13 or above. This heat pump is a long term investment, so spending a bit more up front is easy to justify. Energy savings when swapping out from a conventional central air conditioner/heater can be expected to range from 30% to 60% annually.
How Does a Geothermal System Work?
The certified installer will bury an open or closed polyethylene pipe loop either vertically or horizontally. Sometimes circumstances dictate a compact horizontal "Slinky" installation. This loop is filled with an environmentally friendly antifreeze and water solution. This functions as the unit's heat exchanger.
In the summertime, the unit takes warm air from the home and pumps it through the earth-covered tubes, cooling it off. The opposite happens in the wintertime. The same ductwork as used with a conventional central air conditioner/heater is used to distribute the air.
